1. Field of the Invention
The present invention relates to an optical disc for recording still picture data and audio data to be produced simultaneously with the still picture, an apparatus and a method for recording such an optical disc, and an apparatus and a method for reproducing such an optical disc.
2. Description of the Prior Art
Digital Cameras
Digital cameras for capturing still pictures using the JPEG compression format, formally known as the ISO/IEC 10918-1 standard, have become widely available in the last few years. One reason for the growing popularity of digital cameras is the improved audio-visual (AV) processing capability of modern personal computers (PC).
Images captured by a digital camera can be transferred by various means, including semiconductor memory, floppy disk, and infrared communications, to a PC in a format enabling the image data to be processed and manipulated on the PC. The captured image data can then be edited on the PC for use by presentation programs, word processors, and by Internet content providers.
Digital cameras enabling audio to be captured with still pictures have been more recently introduced. This ability to capture sound with still pictures has helped to further differentiate the digital camera from conventional film-based still cameras.
FIG. 7 shows the relationship between still picture data (JPEG data) and audio data recorded by such a digital camera. As shown in FIG. 7, the still picture data (JPEG data) and audio data are stored in separate files. Each time a picture is taken (recorded), separate JPEG data and audio data files are created.
There are two basic methods for managing the relationship between still picture data (JPEG data) and audio data files. The first, as shown in FIG. 7(a), uses a link manager to maintain the relationship (link) between a JPEG data file and the associated audio data file. The other, as shown in FIG. 7(b), assigns the same root file name (the part of the file name minus the extension, e.g., "xyz" in FIG. 7(b)) to both the JPEG data file and the audio data file.
Using either of the above-described methods, an audio data file can be linked to a particular still picture data file when the picture is captured, and can be changed during any later editing process. That is, if the user decides after taking a picture that the audio associated with that picture is inappropriate or undesirable, different audio data can be selected and linked to the image data on the PC.
The advent of MPEG (Moving Picture Experts Group) standards for handling audio-video data containing moving and still pictures together with audio has also accelerated the development of multimedia products and services based on MPEG standards.
When image data and audio are recorded using the MPEG standard, the audio stream and video stream are multiplexed and recorded as a single system stream as shown in FIG. 6(c). This makes it very difficult to freely change the audio stream associated with a particular video stream after the initial recording. More specifically, to change the audio data recorded for a particular still picture, the still picture data and audio data must be edited together as a single MPEG system stream. This means that the MPEG system stream must first be decoded, and the extracted still picture data and audio data must then be re-encoded as a single system stream after editing. Editing the still picture data and audio data after recording is therefore much more difficult than it is with a conventional digital camera.